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Dissertation
Filtre de Kalman hiérarchisé pour l'estimation d'état dynamique des grands réseaux électriques
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Year: 1988 Publisher: Liège : Université de Liège. Faculté des sciences appliquées,

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Dissertation
Filtre de Kalman hiérarchisé pour l'estimation d'état dynamique des grands réseaux électriques
Author:
Year: 1988

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Dissertation
Etude des performances d'écrans acoustiques d'épaisseur non negligeable
Authors: ---
Year: 1982 Publisher: [S.l.]: [chez l'auteur],

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Book
Filtre de Kalman hiérarchisé pour l'estimation d'état dynamique des grands réseaux électriques
Authors: ---
Year: 1988 Publisher: Liège Université de Liège . Faculté des sciences appliquées

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Dissertation
Static and dynamic modeling of a UPS system in an IP topology
Authors: --- --- --- ---
Year: 2016 Publisher: Liège Université de Liège (ULiège)

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This master thesis is composed of 2 parts. A static part where I use the Newton-Raphson power flow calculation to solve the problem and a dynamic part where I use RAMSES software to study the stability of the system.


Dissertation
Dynamic Modeling of PV Units in response to Voltage Disturbances
Authors: --- --- --- ---
Year: 2016 Publisher: Liège Université de Liège (ULiège)

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This master thesis investigates in a first while a simplified dynamic model of distributed PV units connected at the LV network. Then, this model will be improved focusing on the control and capabilities of the units in agreement with futur grid codes. One of the control that will be implemented is the Low Voltage Fault Ride-Through capability of the units combined with the reactive power support. The simulations will be performed using a MV network 75-bus test system where will be agglomerated equivalent model of PV units at each node. Different scenarios interesting in a System Operator point of view will be further investigated in order to see how the units behave in fault/low voltage situation.


Dissertation
Master thesis : Impact of electromechanical oscillations on operation of distance protections. Analysis of the Belgian grid
Authors: --- --- --- ---
Year: 2018 Publisher: Liège Université de Liège (ULiège)

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Ce travail de fin d'études consiste à mener une analyse du réseau de transmission haute tension belge dans le but de savoir s'il est nécessaire d'installer et d'activer la fonction Power swing des protections de distance. Pour cela, nous devrons effectuer une étude d'oscillations électromécaniques dues d'une part, à l'ajout des charges dans le réseau, des court-circuit sur les lignes de transmission et d'autre part, par le comportement des équipements de production tels que machines synchrones, ... Ainsi, les conclusions de cette étude guideront la décision à prendre.


Dissertation
Master thesis : Dynamics and control of a future off-shore wind power hub
Authors: --- --- --- ---
Year: 2019 Publisher: Liège Université de Liège (ULiège)

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In the past decades, the increased carbon dioxide released by burning fossil fuels has been urging the demand for decarbonisation of our society. However, even if local renewable solutions are necessary, mass-scale production and management will soon be of crucial interest if fossil energies have to be replaced in due course and efficiently. In that context, it is very likely that offshore wind turbines will become an important electricity provider. Nevertheless, nowadays, technical obstacles remain and prevent the global implementation of such technologies. Indeed, the substitution of the classical synchronous machine by converter-based technologies induces a lack of inertia in the network, rendering the system more vulnerable to disturbances and source-outage. The present work aims at highlighting a possible transition technology : the Synchronous Condenser. \

This project is drawn within the context of a large scale and international study: the North Sea Wind Power Hub. The principal idea is to connect onshore network from several countries with an artificial island collecting wind power. Mainly, the efficiency of a Synchronous Condenser to handle the power balance and the voltage control on the island is investigated. Two study cases are performed: a single DC link model and a five link system. Our leading aim is to propose a preliminary tuning of the parameters involved in the VSC controllers and specifically the control of active and reactive power on the island. The control of the active power is based on the rotor speed of the Synchronous Condenser and a Hub Coordinator used to synchronise all DC links together. \

A first approach of the design is conducted through a linear study on the single link system. The poles location allows to determine the required value of the gains to fit specific dynamic constraints. Afterwards, a nonlinear analysis enables to impose additional complementary constraints on the gains. Thanks to those two analyses, the control of the VSC is entirely designed. The main conclusion of this chapter concerns the stability of the system. Indeed, a wide range of values for each gain is determined. Those ranges provide space for the tuning of the gains to fit desired dynamics constraints.\

The final chapter, dedicated to the five link system, focuses on advanced analyses such as $n-1$ criterion or the operating point. The parameters study of the Synchronous Condenser highlights the large possibility in term of size and nominal power to ensure stability. \

The general conclusion of this work is the feasibility of the Synchronous Condenser implementation and the strong stability of the system. It is viable to tune the gains to provide expected behaviours. Therefore, a Synchronous Condenser may be considered as a solution to sustain the current power transition and especially while awaiting the improvement of grid-forming technologies.


Dissertation
Master thesis : Mitigation of voltage sags by a voltage conditioner
Authors: --- --- --- ---
Year: 2019 Publisher: Liège Université de Liège (ULiège)

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Voltage dips occur very often in three-phase power systems. The association of a synchronous machine and a three-point choke can decrease the depth of these and maintain the load voltage within acceptable limits. Simulations are performed for two types of dips resulting from single-phase and three-phase faults. This is done using a load composed of induction machines and of constant admittances. For the first one, the equipment is able to mitigate all the dips. For the second one, more severe, curves showing the duration that can be sustained for a given depth are drawn. The effect of adding inertia to the machine is also analysed and is shown to have a positive impact. Then, the effect of changing the load is investigated. It is found that using a load with full motors or with constant power load have a negative impact.

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